Hydrocarbon wells that have reached their end of life, or which are not feasible for production purposes are typically abandoned. Well abandonment is typically subject to legal and regulatory frameworks for ensuring that wellbore contamination does not occur—either from wellbore fluids leaking into the environment, or from the influx of groundwater into casing strings. Improperly abandoned wells have significant impacts on the surrounding environment, and various regulatory bodies have requirements for the approach taken to properly abandon the wells.
Among the requirements for well abandonment often includes multiple steps that may include: (i) notifying regulatory agencies and landowners (ii) testing the well for likelihood of contamination; (iii) developing an abandonment plan taking into consideration any wellbore issues; (iv) cleaning the internal surface of the well; (v) repairing damaged or other permeable aspects of the well; and (vi) preventing corrosion. Another requirement may include cutting and capping the well below ground level and installing a vented cap.
Due to ongoing testing requirements for abandoned wells, problems arise in the continued monitoring of gas flows. Further, regulators are not often prescriptive in such requirements. It is therefore a critical need to efficiently ensure the working environment of the underground facility is effectively monitored and controlled for hazardous gases and events.